This is a PhraseQuery which is optimized for n-gram phrase query.
For example, when you query "ABCD" on a 2-gram field, you may want to use
NGramPhraseQuery rather than PhraseQuery, because NGramPhraseQuery
will rewrite(IndexReader) the query to "AB/0 CD/2", while PhraseQuery
will query "AB/0 BC/1 CD/2" (where term/position).